This invention relates to an herbicide application system for use in managing vegetation in forests, ranges, rights-of-way, and industrial situations.
In the last three decades, herbicides have emerged as an important vegetation management tool. Nearly 1.5 million acres of commercial forest land are treated each year with herbicides. An even greater acreage is treated annually on range, highway and utility rights-of-way, and industrial lands. The use of herbicides is increasing as costs of alternative methods of vegetation control increase and as new, more effective compounds are developed.
Herbicides can be injected into, sprayed onto, or applied to the soil around individual trees. They can be broadcast over the tops of trees or from below, applied in narrow continuous bands, or spot-applied in a grid pattern. They can be applied from the air, from mechanized ground machines, or by a variety of hand-held equipment. Because of growing concern over the safety and cost-effective use of chemicals and with the development of new, highly specific compounds, interest has increased in the use of hand-held application equipment.
Treatment of vegetation by hand, utilizing a backpack sprayer, allows the operator to spot-treat only the necessary areas, thus saving on chemical costs and large equipment costs. In some situations, hand treatment is more environmentally acceptable. This method, however, has some drawbacks. The two common, commercially available units utilize the following operational principles: (1) Backpack tank with hand pump or compressed gas to charge the sprayer system. Activation of a wand discharges a steady stream of chemical. With this method, accurate dispensing of chemical to a given area is impossible. (2) Backpack tank with a hand pump wand. This system uses an adjustable stroke hand pump in the wand to discharge a predetermined amount of chemical. Operator fatique is the major disadvantage with this method. This invention uses some of the principles of currently available systems but incorporates them into a unique device so that the metered discharge is power assisted for ease of operation. Activation of the device discharges an adjustable but predetermined quantity of chemical. This allows the operator to accurately apply herbicides in a cost-effective manner according to the objectives of the vegetation management prescription for a particular area of land.